I have just came in to possession of a type 99 Arisaka action. The NRA guide shows the thread to be 16.93 m1.5 or approx 17 tpi what is being used? My lathe will cut metric threads (not sure I can) never tried it.. Was Thinking about a Mauser but did not it to blow up and hurt someone.

17,
Cut a test piece to gain confidence.
And do NOT use a Mauser for anything but a paperweight. I have converted all mine to drill rifles.

Now I have to decide on a caliber for the action. So any ideas?

When PO Ackley tested the Arisaka's, he determined they were substantially stronger than every other action out there including Mausers.

Given that, I'd estimate that it's be safe for .22 RF; I had a friend that had a Mauser .22 RF, and he shot it several times that I saw, and it didn't blow up; so I'm sure the Arisaka could handle the round also.

Or throw all caution to the wind, and chamber for 338 Federal.

Or use a fast twist barrel, chamber for .260 remington, handload long bullets and have a rifle that the 6.5 creedmoor wants to be when it grows up.

I've never messed with an Arisaka; don't how easy it would be to lengthen for 30-06 based cartridges. If you can do that, it opens up the world to almost anything useful, without converting to magnum.

What's this?....it's turning into some sort of competition, first the Carcano, then the 93 and now the Arisaka !!!

Just kidding, I'm doing mine in 308W, mainly because I don't have one.

As they are supposed to be so strong, how about one of the short magnums ( a bit of bolt face machining ) or something with a rebated rim...284 or 6.5/284.

Roger

Gives me an interesting thing to think about. I have a small ring mauser 98 that I've been contemplating building something on. Was going to do a 6.5 swede or 7x57. A 260 in the slightly longer 7x57 box would let me seat long bullets out like the Creedmoor, but have the advantage of the larger case capacity of the 260. Would let me take the harder, less resale value, but more fun way to build a rifle.

Anybody with a few dollars can just go buy a savage in 6.5 creedmoor. Might as well be different.

Funny thing, I just keep shaking the tree and different actions fall out. Does seem to be following a pattern. Well I have always heard that He who dies with the most toys wins.
I am not sure on the .22 but its a choice
I have never messed with a Arisaki either but looks like somegthing to keep me busy for a while.

True; anyone with money can just buy a rifle; but unique is better.
I've barreled a few Type 99s, and the bolt literally is set into the barrel for over half of the thread length, so gas has a hard time to escape, when you try to blow them up. Ackley just succeeded in stripping the threads off the barrel, but the action remained fine.
So, choose any caliber you like; preferably starting with the number .35 and above. 33s are ok for smaller stuff. Anything .30 and below strictly pest guns (Elmer's words; remember him?)
30-06? I wouldn't carry one into the field; everyone else will have one.
This is a Type 99; (they are marked 99 Type).

I'll enter the contest! Here's a '38 Carcano with half a '98 bolt, a swept bolt handle, over-the-top mount, '93 (modified) guard for a Colt/Sauer single stack mag, and a Shaw .308 barrel.
As far as I can find, Mr.Ackley (a childhood hero) never did a Carcano or a '93, which of course, I had to give a try. Sheared three bolts off in a '39 Carcano and the action is still (!) serviceable. I firmly believe one could chamber a late Carcano in anything that could fit.

Ok; what?
You sheared three bolts off a Carcano? How? And the action is still good? The bolt is part of the action.....

This is starting to get interesting......

Roger

Well, if you want to go down a rabbit hole, here's a page from a rather long thread I started years ago that old P. O. sent me down. I haven't gone back to it since it ended:

https://castboolits.gunloads.c...ow-up-project/page13

For a less boring trip, here's a pic:

You mean the Receiver is still "good"; not the action.
I hope the Mauser haters don't see this thread; they will have a cow.